D.C. stepping motors are well known. D.C. stepping motors and their associated driving circuitry are disclosed in "Proceedings of the Third International MOTORCON '82 Conference". Sept. 28-30, 1982 Geneva, Switzerland, pages 158 and in "Linear Integrated Circuits" pages 6-129 to 6-134. The latter reference is published by Motorola of Phoenix, Ariz. and discloses a stepping motor drive of the type SAA 1042.
The object of the present invention is to provide a method and circuit for detecting the torque of a stepping motor which can be used in large scale manufacturing operations.